Cenozoic Antarctic Peninsula Temperatures and Glacial Erosion Signals From a Multi‐Proxy Biomarker Study

Terrestrial climate records for Antarctica, beyond the age limit of ice cores, are restricted to few unglaciated areas with exposed rock outcrops. Marine sediments on Antarctica's continental shelves contain past oceanic and terrestrial environments that can provide important insights into Antarctic evolution. The SHALDRIL II (Shallow Drilling Continental Margin) expedition recovered sedimentary sequences from eastern side Peninsula late Eocene, Oligocene, middle Miocene, early Pliocene provides Cenozoic sheet development. Here, we use biomarker data assess atmospheric temperatures glacial reworking Eocene Pliocene. Analyses hopanes n-alkanes indicate increased erosion mature (thermally altered) soil components reworked by erosion. Branched glycerol dialkyl tetraethers bacteria suggest similar air 12°C ± 1°C (1σ, n = 46) months above freezing Miocene timeslices but much colder (and likely shorter) periods thaw during (5°C 1°C, 4) Peninsula. TEX86-based (Tetraether index 86 carbons) sea surface temperature estimates ocean cooling 7°C 3°C (n 10) in 3) Pliocene, consistent deep cooling. Resulting useful constraints model simulations seeking improve understanding response under a range conditions.